A target substance replenishment device may include a first container containing a solid target substance, a first path through which the solid target substance supplied from the first container passes, a first supply switching device switching between a first state where supply of the solid target substance from the first container to the first path is suppressed and a second state where the supply of the solid target substance from the first container to the first path is allowed, a first valve connected to the first path, a second path which is connected to the first valve and through which the solid target substance having passed through the first valve passes, a first detector outputting a first detection signal indicating that the second path is clogged with the solid target substance, and a processor controlling the first supply switching device to the first state based on the first detection signal.